The practice of removal of debris from oil and gas wells is well documented and there are many examples of prior art which include scrapers and brushes to mechanically clean the interior casing of the well. Likewise there are examples of tools designed to remove the debris from the wellbore after it has been scraped and/or brushed. These include junk subs, debris filters, circulation tools, magnets and other similar tools. There also exists several examples of magnetic downhole tools.
There are also examples of tools designed to jet the Blow Out Preventers (BOPs), Wellhead and other cavities found in the wellbore. There also exists in prior art tools which combine the action of BOP jetting and magnetic attraction.
The present invention relates to wells for producing gas and oil and, more particularly, to wellbore cleaning tools, and more particularly, to magnetic wellbore cleaning tools which collect ferromagnetic materials suspended in wellbore fluid.
When drilling an oil or gas well, or when refurbishing an existing well, normal operations may result in various types of metal debris being introduced into the well. Downhole milling produces cuttings which often are not completely removed by circulation. Other metallic objects may drop into and collect near the bottom of the well, or on intermediate plugs placed within the well.
Various drilling and cleaning operations in the oil and gas industry create debris that becomes trapped in a wellbore, including ferromagnetic debris. Generally, fluids are circulated in such a wellbore to washout debris before completion of the well. Several tools have been developed for the removal of ferromagnetic debris from a wellbore. There is a continuing need for a more effective magnetic wellbore cleaning tool.
In one embodiment the magnetic wellbore cleaning tool removes ferromagnetic debris from a wellbore wherein the tool body can be attached to a work string and lowered into a wellbore.
In one embodiment upper and a lower centralizers can be placed on the tool body.
In one embodiment the tool body can have a plurality of longitudinal ridges, each of the plurality of ridges having openings or recesses for holding magnets, wherein the magnets are circumferentially spaced about the body and are aligned in a parallel direction with respect to the longitudinal axis of the tool body.
In one embodiment one or more magnets can be held in place in the opening or recess by a retaining plate. In one embodiment the retaining plate can be slid into a locking position using a slot in a longitudinal ridge. In one embodiment the retaining plate can have one or more openings for exposing a portion of one or more magnets being retained in the opening or recess.
In one embodiment the retainer plate can have a quick lock/quick unlock system wherein in the locked stated the plate is held in place in the slot, and in the unlocked state the plate can slide out of the slot. In one embodiment the quick lock/quick unlock system can include a biased locking connector such as a grub screw.
In one embodiment the plurality of longitudinal ridges can be detachably connected to the tool body. In one embodiment the plurality of ridges can slidably connect to the tool body.
In one embodiment the tool body can include an longitudinal bore which is fluidly connected to the drill string bore, and include a plurality of jetting ports which are fluidly connected to the longitudinal bore of the tool body.
In one embodiment each longitudinal ridge can include at least one jetting nozzle, and in other embodiments can include a plurality of jetting nozzles.
In one embodiment the plurality of ridges when attached to the tool body can form an annular area, wherein the annular area is fluidly connected to the longitudinal bore of the tool body and at least one of the plurality of jetting nozzles.
While certain novel features of this invention shown and described below are pointed out in the annexed claims, the invention is not intended to be limited to the details specified, since a person of ordinary skill in the relevant art will understand that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation may be made without departing in any way from the spirit of the present invention. No feature of the invention is critical or essential unless it is expressly stated as being “critical” or “essential.”